Contamination check near petrol station sites

The Environment Protection Authority says groundwater contamination at three former service station sites in Adelaide may have spread beyond them.

Sites in Gorge Road at Athelstone and Tapleys Hill Road at Royal Park are no longer operating.

But a third in Lower North East Road at Dernancourt is now run by BP.

Independent consultant OTEK Australia has been making an assessment and doing remediation work on behalf of Mobil, which had operated the three sites.

The Authority's Director of Science and Assessment, Peter Dolan, said about 170 households in the areas had been notified of the issue.

"There's groundwater contamination with total petroleum hydrocarbons, or TPH as we call it. It's basically petrol, oils and lubricants that may have leaked from underground storage tanks," he said.

"The actual impact as yet is unknown. What they're trying to do is talk to residents about putting bores down and testing of bores to identify the extent of any contamination.

"Tanks were built to a different standard than what they are now and so it's not uncommon for us to find contamination in the vicinity of old tanks. The plumes are relatively small so the odds of a significant risk are low, but they still need to be investigated."